The Victorian Department of Health is warning of a spike in Legionnaires' disease linked to common household potting mix.
Authorities say there has been a 60 per cent increase in cases linked to the Legionella longbeachae bacteria found in potting mix, soil or compost in the past year.
People are being reminded to stay safe in the garden by wearing a mask and gloves and to make sure they wash their hands after handling or being near the soil.
Legionnaires disease is a type of pneumonia that is caused by bacteria.
Symptoms of the illness are similar to COVID-19 and include headache, fever, cough and muscle aches.
In August, the Victorian Department of Health confirmed they were investigating an outbreak in Melbourne's south-east after the discovery of two confirmed cases in residents of the Cranbourne East area.
Outbreaks in Australia are generally associated with manufactured water systems, including water cooling towers and spa baths.